Generally, for purposes of image data or sound data transmission, isochronous transmission systems, which are suitable for receiving and reproducing synchronized image and sound data, can be used. As a serial bus standard characterized by isochronous transmission, the IEEE-1394 standard can be used.
At a developing stage of applications based on this standard, a bus analyzer is occasionally connected to an IEEE-1394 serial bus so that various operations on the IEEE-1394 serial bus are analyzed. Accordingly, in order to adapt topology of the application development environment to an actual application usage environment, it is important that development tools, such as a bus analyzer, do not operate as a node.
According to the IEEE-1394 standard, a PHY layer (physical layer) that does not operate as a node is not defined. For this reason, a PHY controller LSI having PHY function defined by the IEEE-1394 standard is generally mounted to the bus analyzer which satisfies the IEEE-1394 standard.
However, when the bus analyzer mounted with the PHY controller LSI is connected to the IEEE-1394 serial bus, it is recognized as a node when topology is structured. For this reason, a problem arises as the topology of the application development environment cannot be adapted to the actual application usage environment. Moreover, in case of an application in which the topology is restricted, a problem arises because a bus analyzer cannot be connected to the IEEE-1394 serial bus.